True Random Number Generator (Rng); Introduction; Rng Main Features - ST STM32F423 Reference Manual

True random number generator (RNG)

16 True random number generator (RNG)
16.1

Introduction

The RNG is a true random number generator that continuously provides 32-bit entropy
samples, based on an analog noise source. It can be used by the application as a live
entropy source to build a NIST compliant Deterministic Random Bit Generator (DRBG).
The RNG true random number generator has been validated according to the German
AIS-31 standard.
16.2

RNG main features

•
The RNG delivers 32-bit true random numbers, produced by an analog entropy source
post-processed with linear-feedback shift registers (LFSR).
•
It is validated according to the AIS-31 pre-defined class PTG.2 evaluation methodology,
which is part of the German Common Criteria (CC) scheme.
•
It produces one 32-bit random samples every 42 RNG clock cycles (dedicated clock).
• It allows embedded continuous basic health tests with associated error management
–
• It can be disabled to reduce power consumption.
•
It has an AMBA AHB slave peripheral, accessible through 32-bit word single accesses
only (else an AHB bus error is generated). Warning! any write not equal to 32 bits might
corrupt the register content.
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Includes too low sampling clock detection and repetition count tests.
RM0430 Rev 8
RM0430